Add FIEMAP_EXTENT_SHARED flag

Add FIEMAP_EXTENT_SHARED flag

[Sunil Mushran]

Andrew,

Please could you Ack this patch. This adds a new FIEMAP flag to denote
shared extents which we are using to identify such exents in reflinked
files.

Thanks
Sunil

[PATCH 1/2] fiemap: Add new extent flag FIEMAP_EXTENT_SHARED

[Sunil Mushran]

Patch adds flag FIEMAP_EXTENT_SHARED to denote extents that are
shared with other inodes.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
---
 include/linux/fiemap.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/fiemap.h b/include/linux/fiemap.h
index 934e22d..d830747 100644
--- a/include/linux/fiemap.h
+++ b/include/linux/fiemap.h
@@ -62,5 +62,7 @@ struct fiemap {
 #define FIEMAP_EXTENT_MERGED		0x00001000 /* File does not natively
 						    * support extents. Result
 						    * merged for efficiency. */
+#define FIEMAP_EXTENT_SHARED		0x00002000 /* Space shared with other
+						    * files. */
 
 #endif /* _LINUX_FIEMAP_H */
-- 
1.5.6.5

[PATCH 2/2] ocfs2: Use FIEMAP_EXTENT_SHARED

[Sunil Mushran]

Adds FIEMAP_EXTENT_SHARED flag to refcounted extents.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
---
 fs/ocfs2/extent_map.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index 843db64..cdce5f8 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -786,6 +786,8 @@ int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		fe_flags = 0;
 		if (rec.e_flags & OCFS2_EXT_UNWRITTEN)
 			fe_flags |= FIEMAP_EXTENT_UNWRITTEN;
+		if (rec.e_flags & OCFS2_EXT_REFCOUNTED)
+			fe_flags |= FIEMAP_EXTENT_SHARED;
 		if (is_last)
 			fe_flags |= FIEMAP_EXTENT_LAST;
 		len_bytes = (u64)le16_to_cpu(rec.e_leaf_clusters) << osb->s_clustersize_bits;
-- 
1.5.6.5

Re: [Ocfs2-devel] Add FIEMAP_EXTENT_SHARED flag

[Joel Becker]

On Thu, Dec 03, 2009 at 12:46:50PM -0800, Sunil Mushran wrote:
> Please could you Ack this patch. This adds a new FIEMAP flag to denote
> shared extents which we are using to identify such exents in reflinked
> files.

	These patches are now in ocfs2.git.  If anyone has any concerns,
let me know.

Joel

-- 

Life's Little Instruction Book #464

	"Don't miss the magic of the moment by focusing on what's
	 to come."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker@oracle.com
Phone: (650) 506-8127

Re: [Ocfs2-devel] Add FIEMAP_EXTENT_SHARED flag

[Andreas Dilger]

On 2009-12-17, at 22:10, Joel Becker wrote:
> On Thu, Dec 03, 2009 at 12:46:50PM -0800, Sunil Mushran wrote:
>> Please could you Ack this patch. This adds a new FIEMAP flag to  
>> denote
>> shared extents which we are using to identify such exents in  
>> reflinked
>> files.
>
> 	These patches are now in ocfs2.git.  If anyone has any concerns,
> let me know.


Hi Joel,
are there any plans to submit an e2fsprogs patch to print out the  
"shared" extent flag from "filefrag"?

At first glance it would also seem to make sense to set this flag for  
ext2/3/4 xattrs that are sharing an external extent block.

Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.

Re: Add FIEMAP_EXTENT_SHARED flag

[Sunil Mushran]

Andreas Dilger wrote:
> Hi Joel,
> are there any plans to submit an e2fsprogs patch to print out the 
> "shared" extent flag from "filefrag"?
>
> At first glance it would also seem to make sense to set this flag for 
> ext2/3/4 xattrs that are sharing an external extent block.

Yes, I do have a patch for filefrag which I will push after this
gets into mainline.

Extend FIEMAP to indicate shared extents

[Sunil Mushran]

Please could I get your ACK for these patches.

This adds a FIEMAP extent flag, FIEMAP_EXTENT_SHARED, to indicate
extents that are shared by multiple files. The second patch makes
use of the same in the OCFS2 file system to show such extents in
the reflinked files.

Thanks
Sunil

[PATCH 1/2] fiemap: Add new extent flag FIEMAP_EXTENT_SHARED

[Sunil Mushran]

Patch adds flag FIEMAP_EXTENT_SHARED to denote extents that are
shared with other inodes.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
---
 include/linux/fiemap.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/fiemap.h b/include/linux/fiemap.h
index 934e22d..d830747 100644
--- a/include/linux/fiemap.h
+++ b/include/linux/fiemap.h
@@ -62,5 +62,7 @@ struct fiemap {
 #define FIEMAP_EXTENT_MERGED		0x00001000 /* File does not natively
 						    * support extents. Result
 						    * merged for efficiency. */
+#define FIEMAP_EXTENT_SHARED		0x00002000 /* Space shared with other
+						    * files. */
 
 #endif /* _LINUX_FIEMAP_H */
-- 
1.5.6.5

Extend FIEMAP to indicate shared extents

[Sunil Mushran]

This adds a FIEMAP extent flag, FIEMAP_EXTENT_SHARED, to indicate
extents that are shared by multiple files. The second patch makes
use of the same in the OCFS2 file system to show such extents in
the reflinked files.

Thanks
Sunil

[PATCH 1/2] fiemap: Add new extent flag FIEMAP_EXTENT_SHARED

[Sunil Mushran]

Patch adds flag FIEMAP_EXTENT_SHARED to denote extents that are
shared with other inodes.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
---
 include/linux/fiemap.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/include/linux/fiemap.h b/include/linux/fiemap.h
index 934e22d..d830747 100644
--- a/include/linux/fiemap.h
+++ b/include/linux/fiemap.h
@@ -62,5 +62,7 @@ struct fiemap {
 #define FIEMAP_EXTENT_MERGED		0x00001000 /* File does not natively
 						    * support extents. Result
 						    * merged for efficiency. */
+#define FIEMAP_EXTENT_SHARED		0x00002000 /* Space shared with other
+						    * files. */
 
 #endif /* _LINUX_FIEMAP_H */
-- 
1.6.0.4

Re: [Ocfs2-devel] [PATCH 1/2] fiemap: Add new extent flag FIEMAP_EXTENT_SHARED

[Mark Fasheh]

On Wed, Oct 21, 2009 at 06:05:08PM -0700, Sunil Mushran wrote:
> Patch adds flag FIEMAP_EXTENT_SHARED to denote extents that are
> shared with other inodes.

This looks pretty sane to me. Thanks Sunil.


> Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>

Acked-by: Mark Fasheh <mfasheh@suse.com>
	--Mark

--
Mark Fasheh

Re: [Ocfs2-devel] [PATCH 1/2] fiemap: Add new extent flag FIEMAP_EXTENT_SHARED

[Jamie Lokier]

Mark Fasheh wrote:
> On Wed, Oct 21, 2009 at 06:05:08PM -0700, Sunil Mushran wrote:
> > Patch adds flag FIEMAP_EXTENT_SHARED to denote extents that are
> > shared with other inodes.
> 
> This looks pretty sane to me. Thanks Sunil.

It might be better to have a flag FIEMAP_EXTENT_NOT_SHARED.

Apps which need to know the data is not shared can't safely check
!(flags & FIEMAP_EXTENT_SHARED) because of old kernels which don't set
the flag.

-- Jamie

Re: [PATCH 1/2] fiemap: Add new extent flag FIEMAP_EXTENT_SHARED

[Sunil Mushran]

Jamie Lokier wrote:
> It might be better to have a flag FIEMAP_EXTENT_NOT_SHARED.
>
> Apps which need to know the data is not shared can't safely check
> !(flags & FIEMAP_EXTENT_SHARED) because of old kernels which don't set
> the flag.

I'm probably not understanding your point. Won't the older kernels not set
FIEMAP_EXTENT_NOT_SHARED too.

If this is important, we could always add this flag in the stable kernel
trees. Both sharing of extents and fiemap are relatively new to the kernel.